Noncaseating suppurative granulomatous lymphadenitis in adult onset Still's disease - a diagnostic dilemma in a tuberculosis-endemic region: a case report.

backgroundLymphadenopathy is not an uncommon presentation of adult onset Still's disease: it is present in up to two thirds of patients with adult onset Still's disease. The characteristic appearance of lymphadenopathy is described as intense, paracortical immunoblastic hyperplasia. Changes in light microscopy may resemble lymphoma, but immunohistochemistry reveals a benign polyclonal B cell hyperplasia. CASE PRESENTATION: We describe a 67-year-old Sri Lankan woman who manifested relapsing prolonged fever, raised inflammatory markers, arthralgia, myalgia, transient skin rash, and cervical lymphadenopathy histologically characterized by noncaseating granulomatous adenitis with central suppuration. Due to the fact of high prevalence of tuberculosis in the region, an extensive diagnostic evaluation was done to exclude the possibility of extrapulmonary tuberculosis; unsuccessful therapeutic trials of complete antituberculosis regime reliably excluded the possibility of tuberculosis and strengthened the diagnostic validity. Disease flares were characterized by systemic inflammatory response syndrome with immediate clinical and laboratory response to corticosteroids. After systematic diagnostic workup which ruled out possible malignant, rheumatic, or autoimmune diseases and infections previously described as causes of granulomatous adenitis, our patient was diagnosed as having adult onset Still's disease based on Yamaguchi criteria. She required a trial of indomethacin followed by methylprednisolone pulse therapy and long-term maintenance steroid therapy without steroid-sparing immunosuppressive agents or biological disease-modifying antirheumatic drugs. She achieved full disease remission in 3 months. Reevaluation after 6 months and 1 year did not reveal residual disease activity.

conclusionsTo the best of our knowledge this is the first report of suppurative noncaseating granulomatous lymphadenitis attributed to adult onset Still's disease among Asian or South Asian ethnicities and it is also rarely reported among Europeans and North Americans. It is an extremely challenging situation to diagnose Still's disease with granulomatous lymphadenitis where tuberculosis is highly prevalent. This case highlights the importance of consideration of adult onset Still's disease as a potential diagnosis in a compatible clinical context in the presence of noncaseating granulomatous adenitis and indicates that one should not be misled into a diagnosis of tuberculosis by the fact of the high prevalence of tuberculosis, however, the exclusion of other diagnoses is a prerequisite.